Adjustable curve-ruler.



O. O. HARPER. ADJUSTABLE UU'RV'E RULER. APPLICATION FILED MAY3. 1909.

Patented Feb.22,1910.

WITNESSES Charles Qgburnjlmwfl;

ATTORNEYS UNITEDSTATES. PATENT orrroa.

CHARLES oenuim HARPER, or O AHA, NEBRASKA.

' ADJUSTABLE cUiavE-RULEa.

Specification of Letters Patent.

Patented Feb. 22, 19.10.

Application filed May 8, 1909. Serial No. 493,628.

To all :whom it mag concern: v I

Be 1t known that I, GHAR Es OGBURN HAnrER, a citizen of the UnitedStates, and a resident of Omaha, in the county of Doug-. las and Stateof Nebraska, have invented a, new and Improved Adjustable Curve-Ruler,

of which the following is a full, clear, and.

, exact description.

The invention relates to a curve ruler by which both regular andirregular curves may be made, and consists of an abscissa ruler orstraight edge, a spring ruler, and ordinate rulers adjustable laterallyand longitudinally of the abscissa ruler and arranged at the oppositeend portions and at'an intermediate point of the spring ruler, and theouter or end ordinate rulers having pivotal portions connectin them to.and adjustable and the abscissa ruler being efi'ected by a slidescarried by the'abscissa'ruler or straight this ruler and oneof the edge,and by which I ordinate rulers are adjustably connected;

Fig. 3 is a fragmentaryv edge\ view of the spring ruler, showing theconnection of one of the end ordinatet rulers thereto; Fig. 4 is a sideview of the construction shown in Fig. 3; Fig. 5 is a section throughthe connection between the spring ruler and the interme;'

diate or central ordinate ruleryand Fig. 6 is a plan of the constructionshown in Fig. .5.

An abscissa ruler or straight edge 1Q, a spring rulerll and ordinaterulers 12, 12, and 13, comprise the principal features of the appliance.The ordinate rulers 12, 12 are carried on the end portions of theabscissa ruler, and the ordinate ruler 13 is carried on the abscissaruler between-the rulers 12, 12, the connection between each ordinateruler slide block 14, as shown in detail in- Fig. 2, the block having.slots 15 and 16 arranged at right angles to each other one above theotherand provided with threaded openings in the top to receivebindingxscrews 17 and 18. The slots 15 and 16 of t e blocks'are of suchsize to respective y slidably -fit the erspective view of my im- The endordinate rulers are graduations abscissa ruler and ordinate ruler,these'rulcrs being respectively secured in any desired poslitjign of adustment by the screws 17 an v The plane of the spring ruler ,11 extendsat right-angles to the planes of the other rulers audit. is constructedwith longitudinal slots l9arra'nged at opposite sides of the center Ineach of these slots is slidable a screw 20 having anangular portionadjacent to the head to prevent it. from turning, and I provided with athumb nut 21 at the outside.

Each screw 20 passes through a bracket 22 having an inwardly-incliningarm arranged at approximately right-an les'to that portion of thebracket through, which the screw 20 passes, and provided with anupwardlyprojecting stud 23 which passesthrough the apertured end of theadjacentordinate ruler, and is rovided with a-thumb-nut 24' to bind thisru er and the bracket together. This manner of connecting the outerofend ordi nate ruler to the spring ruler admits of the brackets '22occupying any position on the spring ruler within the limits of theiradjustment and making any required angle with the ordinate rulers, as isobviously necessary in adjusting the latter on the ab scissa ruier. Thecenter of the spring ruler is fixed to the outer end of the intermediateordinate ruler 13'by a screw 25, which, aS-

shown in Figs. 5 and 6, is threaded into a metal end-piece 26 riveted orotherwise se cured to this'ruler and of reduced 'width at its extremityin order that it will not present any substantial interference with thedrawspring gage.

In adjusting theiustrument to make any regular curve, such as asemi-ellipse, the ordinate ruler 13 is moved to the center and drawnclose to the abscissa rulerand secured against both lateral andlongitudinal movement by tightening the screws 17 and then moved at 'ingofthe curve from.the outside of the equal distances [from theintermediate ordlnate'ruler, which may be determined by the on theabscissa ruler. In this position further lateral movement of-theordinate rulers 12 is prevented 'by ti htening the screws 17, afterwhich each of t ese ers is movedoutwardly. a distance necessary to 18,which hold them place, are tightened and the thumb-nuts 21 and 24, whichduring 'ive thedes'ired curve, when the screws the lateral movement ofthe ehd ordinate rulers are loosened, are then tightened. With .nes'sfor the drafting of the curverequired.

B the adiustment of the ordinate rulers 12, su stantia ly ang; ;regularor irregular curve may be obtaine and the size of the-curve may bevaried by substituting for the spring i ruler 11, other like rulers offierent length. Having thus described my invention, I claimas new and,desire to secure by Letters Patent:

.1. The combination of an abscissa ruler, a

s ring ruler, ordinate rulers carried by the ahscissa ruler,longitudinally and laterally adjustable thereon, and brackets slidablealong the length of the spring ruler and each having a pivotalconnection with one of the ordinate rulers.

2. The combination of an abscissa ruler, blocks slidable on the abscissaruler, or'dinate rulers slidably supported on the blocks, alongitudinally-slotted spring ruler, bracke'ts pivotall connected to theordlnate rulers, and inding screws adjustably con ruler, means securingthe spring ruler at an intermediate point to one of the ordinate rulers,and means adjustably connecting the end portions of the spring ruler tothe other ordinate rulers.

4. The combinationof an abscissa ruler,

blocks slidable on the abscissa ruler, a spring ruler, and ordinaterulers slidable in the blocks, with one of the ordinate rulers connected to the spring ruler intermediate its length and the otherordinaterulers eachhavlng a sliding connection with an end portion of the springruler;

In testimony whereof'I havesigned my name to this specification in thepresence of two subscribing witnesses.

CHAR-LES OGBURN HARPER.

Witnesses: I

" A. BLTEBBENS, A. B; WARREN.

